HP 8753E manual ‘able 2-2. Gate Characteristics, Fiiure 2-61. Gate Shape

‘able 2-2. Gate Characteristics

Gate	Pas&and	Sidelobe	cntoff	Gate spfm
shape	Eipple	LeVdS
Gate Span Minimum	zto.1 dEs	-48dEt	lA/Freq Span	B.S/Freq Span
Normal	50.1 dB	-68 dB	2.8/Freq Span	6.6/Freq Span
Wide	fO.l dB	-57 dB	4.4FreqSpan	8.8Preq Span
MaXimUIlI	fO.O1 dB	-70 dB	12.7PreqSpan	26.4Freq Span
I NOTE: With 1601 frequency points, gating is available only in the bandpass mode.					I

The passband ripple and sidelobe levels are descriptive of the gate shape. The cutoff time is the time between the stop time (-6 dB on the filter skirt) and the peak of the first sidelobe, and

is equal on the left and right side skirts of the hlter. Because the minimum gate span has no passband, it is just twice the cutoff time.

CHl A/R log MAG 10 dB/ REF -70 dB

P?

CHl START-7 ns STOP 7 ns pg6121d

Fiiure 2-61. Gate Shape

13. ‘lb see the effect of the gating in the frequency domain, press:

This places the gated response in memory. F’igure 2-62 shows the effect of removing the RF leakage and the triple travel signal path using gating. By transforming back to the frequency domain, we see that this design change would yield better out-of-band rejection.

2-86 Making Measurements